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EXPERIMENTAL INVESTIGATIONS OF 33
ACCELERATIONS AND VIBRATIONS ON VEHICLES AND BOATS

Table 7: VDV in each axis and totals for both devices.

VDV Mti 200[m/s1.75] Mti 700[m/s1.75] Total[m/s1.75]
X-Axis 2500.975 20120.73 20121.93
Y-axis 2049.075 24756.79 24757.08
Z-axis 43831.63 80178.02 81911.29
Total 14.831 18.805 20.41

The track is given in Figure 5 and VDV of Mti200 and Mti700 in each axis and totals on 2nd of
April 2015 track is shown in Table 7. It can be seen that VDV due to vibration was calculated to
be 14.83 ms-1.75 and 18.81 ms-1.75 for Mti200 and Mti700 respectively, and the total VDV is
20.41.

3.2 Measuring Impacts on 4.7m Inflatable Lifesaving Boat

The experiment has done with a rigid inflatable 4.70 meters Mercury boat of Istanbul AFAD at
Marmara Sea. The boat was equipped with two tri-axial accelerometers. Two trials on the same
day approximately five minutes apart were undertaken on board. The duration of each trial was
approximately 7 and 8 minutes, respectively. Both trials contained a mixture of head, beam and
following seas. The sea state was estimated to be 1 on both trials. Two passengers accompanied
an experienced Istanbul AFAD pilot on both trials. The average speed in open water during both
trials was between 15 knots and 20 knots depending on the direction of travel relative to the
waves. The axes of the accelerometer were aligned such that the Z axis measured vertical
acceleration or heave, the Y axis measured transverse or lateral acceleration and the X axis fore-
aft accelerations. The X, Y and Z axes of the rate gyros were aligned to measure roll, pitch and
yaw, respectively. Basic vehicle parameters of the boat are given in Table 8. Similar
measurements can be found on Riley[25] and Ullman [26].

Table 8: Boat Specifications Heavy-Duty 470 XS

Specification Value
Engine Output 25 kw

Overall length 470 cm

Length inside 332 cm

Overall beam 216 cm

Maximum Load 1200 kg

Boat’s Weight 160 kg

Beam Inside 108 cm

Tube Diameter 54 cm

Sayı 3, 2015 GiDB|DERGi